Data messaging services are essential in present day network communications systems. E-mail, wireless file transfers, and networked applications sharing common files are just a few of the many types and uses of data messaging services available over present day local area networks (LANs), wide area networks (WANs), and the internet. In today's information based society, both people and computer based equipment have come to rely on sending and receiving information almost instantaneously.
A critical point in providing or receiving data messaging services is the ability to connect to the network. In present day network systems, it is not necessary, and in fact is not even typical, for each user to connect directly to the network. Rather, a typical user remotely connects to the network via a modem by dialing a conventional telephone number of an access point. The access point is typically a switch owned by a network service provider through which remote callers are authenticated as authorized users and then connected to the network. Accordingly, one limitation of present day networked systems is the requirement that a user have the ability to connect to the network, either directly or remotely. As witnessed by the phenomenal growth of the internet and world wide web, and by the growth in number of both network service providers and network service provider members, connecting to a communications network is not generally problematic.
One area, however, where actual connection to a communications network is quite problematic and sometimes even impossible, and which accordingly results in the general unavailability of in-flight data messaging services, is aboard an airborne aircraft. The reasons for this are multifold. First, most local communications networks are ground based and use line of sight (LOS) communications links. These types of communication systems work well when each node in the communication network is stationary. However, an en route aircraft travels far distances, typically across several geographical ranges and out of range of any single ground based communication system. Furthermore, even in cellular radiotelephone communications systems, which provide communication links for moving subscriber units, the ground based switching centers, or "cells", must each be in communication and are required to conduct a lengthy subscriber authentication process in order to service a "roaming" subscriber unit that is out of range of its "home" cell but which is within the range of control of a "visited" cell. This results because only the home cell of a subscriber has full access to its authentication information (e.g., the factory set electronic serial number (ESN) and corresponding mobile identification number (MIN), which uniquely identifies the subscriber unit from other subscriber units, the subscriber unit's secret cipher key and method of generating a call cipher key). Accordingly, the overhead involved in sending a message is quite high, impractical, and even impossible when the aircraft flies out of range of any cell in the cellular network. Finally, in order to send a data message from one node in a communication network to another, the location of the destination network node must be known. Since an aircraft usually travels in and out of the range of communication of several ground based communication systems, the location of the aircraft is always changing and hence not necessarily known. Accordingly, it is very difficult to configure an airborne aircraft to operate as a network node within any given communication system.
Accordingly, a need exists for a system and method for providing a data message routing and delivery service between ground based networks and airborne aircraft.